Controversial new guidelines say the test should no longer be routine.

Women in their 40s should not get routine mammograms for early detection of breast cancer, according to new guidelines from the U.S. Preventive Services Task Force.

The task force recommends that before getting a mammogram, women ages 40 to 49 should talk to their doctors about the risks and benefits of the test. They should then decide if they want to be screened.

Routine mammograms are recommended every two years for women ages 50 to 74. Risks and benefits for women age 75 and above are unknown, the task force (comprised of 16 health care experts) said.

Previously, the task force had recommended routine screenings every year or two for women age 40 and up.

"All we are saying is, at age 40, a woman should make an appointment with her doctor and have a conversation about the benefits and harms of having a mammography now versus waiting to age 50," Dr. Diana Petitti, vice chair of the task force, told CNN.

Approximately 15 percent of women in their 40s detect breast cancer through mammography, the study found. However, many other women experience false positives, anxiety, and unnecessary biopsies as a result of the test.

But not everyone agrees with these new guidelines.

"We disagree with their conclusions," Dr. Therese Bevers from the University of Texas M.D. Anderson Cancer Center said of the task force. "You have to screen more women. It's the value we put on zero women dying."

Some doctors fear this new study may turn women away from being screened at all, or that insurance coverage of mammograms could be dropped based on the new recommendations.

A spokeswoman for American Health Insurance Plans told CNN that insurance providers may revisit how they measure a health plan's performance based on the updated guidelines, but adds that coverage is unlikely to be dropped.

This year, nearly 200,000 women will be diagnosed with breast cancer, according to the American Cancer Society.

What do you think of these new guidelines?